Magneto-mechanical converter

ABSTRACT

The proposed magneto-mechanical converter comprises a magnet system (2) and a core (3) at least one part (34, 36) of which is made of a magneto-strictive material. The magnet system (2) comprises a main magnetic field source (4) which in the example shown can be mounted on the magnetic circuit (21). The main magnetic field source is a permanent magnet (5). The magnet system (2) is mounted in the housing (1) in such a way that it can rotate about the core (3). The geometrical axis (15) of relative rotation of the core (3) and magnet system (2) is oriented in such a way that, during the relative rotation referred to, the magnetic flux in the magneto-strictive parts (34, 36) of the core alters and in turn causes changes in the linear dimensions of the core (3). In the example shown, the magnet system (2) includes an auxiliary magnetic field source (22) in the form of a permanent magnet (5&#39;) mounted on the magnetic circuit (33). The magnetic field sources (4, 22) consist of pairs of magnetic components (23, 24, and 25, 26). The core (3) in the example shown consists of three sections (34, 35, 36), the outer sections (34, 36) being made of magneto-strictive material. In the example shown, one (e.g. auxiliary magnetic field source (22) is mounted immovably in relation to the core (3), while a second (e.g. main) magnetic field source (4) rotates about the stationary core (3).

FIELD OF THE INVENTION

The present invention relates to electrotechnology and means ofautomation and can be used as a device for adjustable displacements ofobjects, primarily for precise positioning of the actuators of machinesand mechanisms.

PRIOR ART

Magneto-mechanical converters with an electromagnetic system, containingan excitation coil, serving as a magnetic field source, and amagnetostrictive core, made of a rare-earth metal-iron alloy, are known(Research of highly magnetostrictive materials on the basis ofrare-earth metals (REM), report of the Physical Faculty of MGU (MoscowState University), Subject 46/75, 1977, Moscow, p. 3). The magnitude ofdisplacements of the mobile part of the referred to magneto-mechanicalconverter is relatively small. Besides, the use of the magnetic fieldsource in the form of an electric excitation coil requires significantenergy consumption, in order to maintain the specified parameters of themagnetic field in the process of operation, which complicates the use ofthe converter as a positioner or vibrator.

A magneto-mechanical converter with a magnet system, including amagnetic field source in the form of an electric excitation coil, and acore at least one part of which is made of a magnetostrictive material,and that is connected with an actuator movable relative to the housing,is also known (SU, Author Certificate No. 765913).

Main drawbacks of the known magneto-mechanical converters include highenergy consumption of the magnetic field source, which typically isimplemented in the form of an electric excitation coil, due to the factthat in order to maintain the necessary parameters of the magnetic fieldwhile setting and keeping unchanged the specified linear dimensions ofthe core it is required to continuously supply current through theexcitation coil of the magnetic field source. And what is more, for thereferred to known technical solution, an additional heating of themagnet system and material of the core usually occurs, which results inthe necessity of creating a complicated system of cooling andcompensation of temperature changes of the linear dimensions of thecore. The aforementioned drawbacks are the cause of increase of thedevice volume and mass on the whole, and as a result the knownmagneto-mechanical converters do not provide sufficient accuracy insystems for precise positioning. In addition, high energy consumptioncomplicates the use of the converter as a vibrator.

SUMMARY OF THE INVENTION

It is an object of this invention to design a magneto-mechanicalconverter, that would allow decrease of power consumption and themagneto-mechanical converter volume and mass with a simultaneousincrease of the range and discreteness of changes of the lineardimensions of the core, as well as provide possibilities for theconverter to work as a vibrator.

It is achieved by the fact that, in the magneto-mechanical converter,comprising a main magnetic field source, and a core with at least onepart made of a magnetostrictive material, connected with the actuator,which is movable relative to the housing, according to the invention,the main magnetic field source is a permanent magnet, the core and themagnet system are mounted in the housing with the capability of relativerotation, where the axis of relative rotation of the core and the magnetsystem is oriented in such a way that linear dimensions of the corechange in the process of the above-mentioned relative rotation due tothe alteration of the magnetic flux in the core.

It is desirable to place the core in the designed position in such a waythat the geometrical center of at least one of its parts, made of amagnetostrictive material, is in one of the zones of the magnet systemwhich corresponds the maximum of intensity of the magnetic field of thissystem.

It is further desirable to orient the axis of relative rotation of thecore and the magnet system nonparallel with the vector of intensity ofthe magnet system magnetic field in the geometrical center of at leastone part of the core, made of a magnetostrictive material, located inthe designed position, and/or toward the geometrical axis, of at leastone part of the core, made of a magnetostrictive material, orientedalong the direction of the displacement of the actuator and passingthrough the geometrical center of the mentioned part made of amagnetostrictive material.

In some cases it is advantageous to have the axis of relative rotationof the core and of the magnet system passing through the geometricalcenter of at least one part of the core made of a magnetostrictivematerial.

As the optimum, the axis of relative rotation of the core and the magnetsystem should be positioned perpendicularly towards the mentionedgeometrical axis of at least one part of the core, made of amagnetostrictive material, passing through the geometrical center of thementioned part along the direction of the displacement of the actuator,and towards the vector of intensity of the magnet system magnetic fieldin the geometrical center of at least one part of the core, made of amagnetostrictive material, located in the designed position.

It is quite reasonable that the permanent magnet, serving as the mainmagnetic field source comprises at least two magnetic parts, that form agroup and are located in one plane in such a way that the vectors ofmagnetization of at least two adjacent magnetic parts are oriented inopposite directions.

It is further advisable to have a magnet system, containing an auxiliarymagnetic field source in the form of a permanent magnet, which wouldcomprise at least two magnetic parts that form a group, and are locatedin one plane, so that the vectors of magnetization of at least twoadjacent magnetic parts are oriented in opposite directions, where bothmagnetic field sources should be positioned mirror-symmetrically inrelation to the plane located perpendicularly towards the axis ofrelative rotation of the core and the magnet system, and the groups ofmagnetic parts should be oriented in such a way that the vectors ofmagnetization of the oppositely located parts of the mentioned magneticfield sources are oriented along the axis of relative rotation of thecore and the magnet system in opposite directions.

The core can comprise three parts, which are consecutively located alongthe geometrical axis of at least one part of the core, made of amagnetostrictive material, which passes through the geometrical centerof this part along the direction of displacement of the actuator, wherethe outer parts of the core are made of a magnetostrictive material, andits middle part is made of a material with a modulus and an elasticlimit, that are no less than the modulus and elastic limit of thematerial of any adjacent outer part, respectively.

It is possible for the material of one outer part of the core to have apositive magnetostriction, and for the material of the other outer partof the core to have a negative magnetostriction.

It is desirable to have a core, comprising two identical parallellylocated parts, made of a magnetostrictive material, and it is reasonableto place the mentioned parts centrally symmetrically in relation to thegeometrical axis of relative rotation of the core and the magnet system.

It is quite reasonable to have groups of magnetic parts, serving asmagnetic field sources, implemented in the form of disks, and magneticparts in the groups implemented in the form of sectors.

It is desirable to have a magnet system supplied with a magneticcircuit, and to have a magnetic field source located on the magneticcircuit on the side facing the core.

It is further reasonable to have the axis of the easiest direction ofmagnetization of the material of at least one part of the core, made ofa magnetostrictive material, coincident with the direction of thegeometrical axis of at least one part of the core, made of amagnetostrictive material, passing through the geometrical center of thementioned part along the direction of the displacement of the actuator.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in greater detail with reference toembodiments which are represented in the accompanying drawings, wherein:

FIG. 1--depicts a general diagram of the magneto-mechanical converter ofthe present invention with a magnet system, including one main magneticfield source, comprising a single magnetic part, and a core, comprisinga single magnetic part, made of a magnetostrictive material, thegeometrical center of the core part is located on the geometrical axisof relative rotation, oriented nonparallel (at a certain angle not equalto 0°) in relation to the vector of intensity of the magnet systemmagnetic field and to the geometrical axis of the core part, made of amagnetostrictive material.

FIG. 2--section along the line II--II of FIG. 1.

FIG. 3--axonometry of the main magnetic field source according to FIG.1.

FIGS. 4 and 5--the diagram of control of the embodiment disclosed inFIG. 1 (the core is shown as if it rotates in relation to the stationarymagnet system).

FIG. 6--depicts a general diagram of another embodiment of the presentinvention as shown in FIG. 1, in which the main magnetic field source ismounted on the magnetic circuit, and the geometrical center of the partof the core, made of a magnetostrictive material, is displaced inrelation to the geometrical axis of relative rotation, oriented at anangle of 90° to the vector of intensity of the magnetic field of themagnet system and to the geometrical axis of the part of the core, madeof a magnetostrictive material, and located in the designed position.

FIG. 7--section along the line VII--VII of FIG. 6.

FIG. 8--axonometry of the main magnetic field source with the magneticcircuit shown in FIG. 7.

FIGS. 9 and 10--diagram of control of the embodiment of themagneto-mechanical converter shown in FIG. 6 (the core is shown as if itrotates in relation to the stationary magnet system).

FIG. 11--depicts a general diagram of the embodiment of the presentinvention shown in FIG. 6, in which the magnet system is supplied withan auxiliary magnetic field source, mounted on an auxiliary magneticcircuit, where each source of the magnetic field comprises two magneticparts, and the core comprises two parallel parts, made of amagnetostrictive material, located centrally-symmetrically in relationto the axis of rotation of the magnet system.

FIG. 12--section along the line XII--XII of FIG. 11.

FIG. 13--axonometry of the main and auxiliary magnetic field sourceswith magnetic circuits shown in FIG. 11.

FIGS. 14 and 15--diagram of control of the embodiment shown in FIG. 11(the core is shown as if it rotates in relation to the stationary magnetsystem).

FIG. 16--depicts a general diagram of the embodiment of the presentinvention shown in FIG. 11, in which the core comprises threeconsecutively positioned parts, the outer ones of which are made of amagnetostrictive material, e.g., with a positive magnetostriction, themain and auxiliary magnetic field sources are mounted with thecapability of relative rotation, and the axis of rotation of the magnetsystem passes through the middle part of the core.

FIG. 17--section along the line XVII--XVII of FIG. 16.

FIG. 18--axonometry of the magnet system shown in FIG. 16.

FIGS. 19 and 20--diagram of control of the embodiment of the inventionshown in FIG. 16 (the rotation of the main magnetic field sourcerelative to the core and auxiliary magnetic field source is shown).

FIG. 21--depicts a general diagram of the embodiment of the inventionshown in FIG. 16, wherein the magnet system is provided with a closingmagnetic circuit, the main and auxiliary magnetic field sources comprisethree parts (each of them), and outer parts of the core are made ofmaterials with a magnetostriction of a different sign.

FIG. 22--section along the line XXII--XXII of FIG. 21.

FIG. 23--axonometry of the magnet system shown in FIG. 21.

FIGS. 24 and 25--diagram of control of the embodiment shown in FIG. 21(the core is shown as if it rotates in relation to the stationary magnetsystem).

FIG. 26--depicts another general diagram of the embodiment of themagneto-mechanical converter shown in FIG. 11, in which the main andauxiliary magnetic field sources are both implemented in the form ofdisks, and magnetic parts are implemented in the form of sectors.

FIG. 27--section along the line XXVII--XXVII of FIG. 26.

FIG. 28 and 29--depicts the magnet system shown in FIG. 26 inperspective with regard for the mutual location of the magnetic parts ofthe main and auxiliary (respectively) magnetic field sources in thedesigned position.

FIGS. 30 and 31, FIGS. 32 and 33--diagrams of control of the embodimentof the invention shown in FIG. 26, i.e., projections of the parts of thecore on the main and auxiliary magnetic field sources are shown in thedesigned position of the core (FIGS. 30 and 31) and after rotation ofthe mentioned sources in opposite directions (FIGS. 32 and 33) at thesame angle (the vectors of magnetization of the magnetic parts of themain and auxiliary magnetic field sources and of the core are shown bycircles with dots and crosses in the center).

PREFERRED EMBODIMENTS OF THE INVENTION

The magneto-mechanical converter (FIG. 1, or 6, or 11, or 16, or 21 or26) according to the invention comprises the housing 1, in which amagnet system 2 and a core 3 (made, e.g., of alloys TbFe₂, and/or SmFe₂,with giant magnetostriction) are mounted.

The magnet system necessarily includes the main magnetic field source 4in the form of a permanent magnet 5. The core 3 is positioned with theminimal technologically admissible gap relative to the main magneticfield source 4. The mentioned technological gap ensures free rotation ofthe main magnetic field source 4(i.e., without any friction on thecorresponding surface of the core 3).

Further, the magneto-mechanical converter comprises an actuator 6, made,e.g., in the form of a pusher 7, which has the capability ofreciprocating displacement due to the availability of an elasticcomponent 8 and the kinematic connection with the butt-end 9 of the core3 turned towards the mentioned pusher 7. The opposite (relative to thementioned butt-end 9) butt-ends 10 of the core 3 is fixed firmlyrelative to the housing 1 e.g., on the support made of a non-magneticmaterial.

The geometrical axis 12 of symmetry of at least one part of the core 3,made of a magnetostrictive material, is oriented along the direction ofthe displacement of the actuator 6 and mainly coincides with thedirection of the axis 13 of the easiest direction of magnetization ofthe magnetostrictive material of the core 3 (in FIG. 2, or 7, or 12, or17, or 22 or 27 the geometrical axis 12 and axis 13 of the easiestdirection of magnetization are co-located and are shown by adot-and-dash line).

The core 3 in the designed position is located in such a way that thegeometrical center 14, of at least one of its parts, made of amagnetostrictive material, is in one of the zones of the magnet system2, and the zone corresponds to the maximum of intensity of the magneticfield of the magnet system 2.

The core 3 and the magnet system 2 are mounted in the housing 1 with thecapability of relative rotation (generally the magnet system 2 rotates,and the core 3 is stationary). The axis of relative rotation of the core3 and the magnet system 2 is oriented nonparallel (i.e., at an angle,different from 0°, in FIG. 1 and at an angle, equal to 90°, in FIGS. 6,11, 16, 21 and 26 in the various embodiments) in relation to the vectorof intensity of the magnetic field of the magnet system 2 in thegeometrical center 14 of the part of the core 3, made of amagnetostrictive material. This allows the linear dimensions of the core3 to be changed as much as possible in the process of the mentionedrotation due to the alteration of the direction or magnitude of themagnetic flux in the core.

In the embodiment of the invention shown in FIG. 1 the main magneticfield source 4 of the magnet system 2 comprises one magnetic part 16(shown in axonometry in FIG. 3). In this case the magnetic part 16functions as the magnet system 2. The core 3 is implemented in the formof a single part 17, made of a magnetostrictive material. The magnetsystem 2 is mounted in the housing 1 on the axis 18 with the capabilityof rotation about the stationary core 3. The geometrical axis 15 ofrelative rotation of the magnet system 2 in this embodiment of theinvention passes through the geometrical center 14 of the part 17 of thecore 3, made of a magnetostrictive material, and is oriented at anangle, not equal to 0°, in relation to the vector of intensity of themagnetic field of magnet system 2 and to the geometrical axis 12 ofsymmetry of the part 17 of the core 3. The rotation is implemented withthe help of the rotation drive 19, which can be represented e.g., by astep electric motor (during automatic control), or any known rotationdrive of a mechanical type (during manual control). The axis 18 ismounted in the housing on the bearing 20.

The above-described embodiment of the invention has the magnet system 2that comprises only one main magnetic field source 4, comprising asingle magnetic part 16, and the core 3, that comprises a single part17, made of a magnetostrictive material, and the geometrical center 14of the magnetostrictive part 17 of the core 3, coinciding with thegeometrical axis 15 of rotation of the magnet system 2.

This embodiment of the invention is given to illustrate the possibilityof practical realization of the magneto-mechanical converter, in whichthe geometrical axis 15 of rotation of the magnet system 2 is orientedat an angle not equal to 0° towards the vector of intensity of themagnetic field of magnet system 2 and towards the geometrical axis 12 ofsymmetry of the part 17 of the core 3.

It is advisable to use the above-described embodiment of the inventionin small-sized mechanisms for a single-coordinate displacement, e.g., insingle-coordinate modules for precise positioning, or insingle-coordinate vibrators of low capacity.

However, there are other possible embodiments of the invention.

In the further embodiment shown in FIG. 6 the magneto-mechanicalconverter is basically similar to the previous one (FIG. 1), but differsfrom it by the fact that the geometrical center 14 of the part 17 of thecore 3, made of a magnetostrictive material, is not coincident with theaxis 15 of relative rotation of the magnet system 2. The axis 15 of therelative rotation of the magnet system 2 is oriented at an angle, equalto 90°, towards the vector of intensity of the magnetic field of magnetsystem 2 and towards the geometrical axis 12 of symmetry of the part 17of the core 3. Furthermore, the main magnetic field source 4 is mountedon the magnetic circuit 21 of the magnet system 2 on the side facing thecore 3.

It is advisable to use this embodiment as well as the previous one, insmall-sized mechanisms for a single-coordinate displacement, e.g., insingle-coordinate modules for precise positioning or insingle-coordinate vibrators of low capacity.

The embodiment of the invention shown in FIG. 11 is basically similar tothe previous one of FIG. 6, but differs from it by the fact that themagnet system 2 comprises an auxiliary magnetic field source 22implemented as a permanent magnet 5'. The main and auxiliary sources 4and 22, respectively, of the magnetic field of the magnet system 2 arepositioned mirror-symmetrically in relation to the plane, locatedperpendicularly towards the geometrical axis 15 of relative rotation ofthe magnet system 2 and passing through the geometrical axes 12 ofsymmetry of the magnetostrictive parts 28, 29. The auxiliary source 22is mounted with the minimal permissible technological gap between it andthe core 3.

Due to the availability of the mentioned technological gap, freerotation of the auxiliary source 22 of the magnetic field is ensured(i.e., without any friction on the corresponding surface of the core 3).Each of the sources 4 and 22 of the magnetic field comprises twomagnetic parts 23, 24 and 25, 26, respectively, located in the sameplane and forming groups (the first group--parts 23, 24, and the secondgroup parts 25, 26). The magnetic parts 23, 24 and 25, 26, respectively,in each group formed by them, are located in such a way that the vectors27 of magnetization of adjacent magnetic parts 23, 24 and 25, 26 areoriented, in the groups formed by them, in opposite directions. Thegroups of magnetic parts 23, 24 and 25, 26 are oriented relative to eachother in such a way that in the designed position the vectors 27 ofmagnetization of the oppositely positioned parts 23 and 25, 24 and 26are also oriented in opposite directions along the geometrical axis 15of relative rotation of the core 3 and the magnet system 2.

The core 3 is implemented of two identical parts 28 and 29 that have thesame magnetostriction sign and magnitude and positioned in parallel. Therotation of the magnet system 2 is realized on the axis 30, mounted inthe housing 1 on the bearings 31, 32. The auxiliary source 22 of themagnetic field is mounted on the magnetic circuit 33 similar to the mainsource 4 of the magnetic field.

It is advisable to use this embodiment in the mechanisms for asingle-coordinate displacement, e.g., in the single-coordinate modulesfor precise positioning, or in single-coordinate vibrators.

In the embodiment of FIG. 16 the magneto-mechanical converter isbasically similar to the previous embodiment shown in FIG. 11, butdiffers from it by the fact that the core 3 comprises three parts 34,35, 36, which are consecutively positioned along the geometrical axis 12of symmetry of parts 34, 36 of the core, made of a magnetostrictivematerial, oriented along the direction of displacement of the pusher 7.The parts 34, 36 of the core 3 are outer parts. The middle part 35 ofthe core 3 is made of a material with a modulus and an elastic limitthat are at least no less in magnitude than the modulus and elasticlimit of any of its adjacent outer parts 34, 36 of the core 3,respectively. For example, part 35 of the core 3 can be made of 12X18H9Tstainless steel or BT9 titanium alloy. Both outer parts 34 and 36 of thecore 3 are made of materials with magnetostriction of the same sign(both positive, or both negative) (e.g., of an alloy TbFe₂). Theauxiliary source 22 and the main source 4 of the magnetic field aremounted on the axis 30 with the capability of relative rotation.

It is advisable to use this embodiment in the mechanisms for asingle-coordinate displacement, e.g., in the single-coordinate modulesfor precise positioning.

In the embodiment shown in FIG. 21 the magneto-mechanical converter isbasically similar to the previous embodiment shown in FIG. 16, butdiffers from it by the fact that the main and auxiliary magnetic fieldsources 4 and 22, respectively, each comprises three magnetic parts 37,38, 39 and 40, 41, 42, respectively, that form groups located in thesame plane. One outer part 34 of the core 3 is made of a material with apositive magnetostriction (e.g., of an alloy TbFe₂). The other outerpart 36 of the core is made of a material with a negativemagnetostriction (e.g., of a SmFe₂ alloy). In addition to this, themagnet system 2 is provided with a closing magnetic circuit 43, and themain and auxiliary sources 4, 22 of the magnetic field are fixed firmlyon the axis 30.

It is advisable to use this embodiment, like the previous one depictedin FIG. 16, in mechanisms for a single-coordinate displacement, e.g., insingle-coordinate modules for precise positioning.

In the embodiment shown in FIG. 26 the magneto-mechanical converter isbasically similar to the embodiment of FIG. 11, but differs from it bythe fact that the main and auxiliary sources 4 and 22, respectively, ofthe magnetic field are made in the form of disks, and the magnetic parts44, 45, 46, 47, 48, 49, 50, 51 and 52, 53, 54, 55, 56, 57, 58, 59, ingroups forming the disks, respectively, of the main and auxiliarysources 4 and 22 of the magnetic field are implemented in the form ofsectors. The auxiliary source 22 of the magnetic field is mounted withthe capability of rotation in the housing 1 on the axis 60 by means of abearing 61 and is rotated by an individual drive 62 of the rotativemovement.

It is advisable to use this embodiment in single-coordinate vibrators ofhigh capacity, as it allows one to obtain high power of mechanicalvibrations of the pusher 7 (as compared to the previously describedembodiments) while preserving the frequency of rotation of the sources 4and 22 of the magnetic field of magnet system 2.

In all the above-described embodiments the sources 4 and 22 of themagnetic field can be mounted in the cases 63 and 64, respectively, madeof a non- magnetic material, and the axis 13 of the easiest direction ofmagnetization of the material of magnetostrictive parts 17, 28, 29, 34,36 of the core 3 coincides in direction with the geometrical axis 12 ofsymmetry of mentioned parts 17, 28, 29, 34, 36 of the core 3, passingalong the direction of displacement of the pusher 7.

In FIG. 3, 8, 13, 23, 28 and 29, arrows indicate lines of forces 65 ofthe magnetic induction of the magnet system 2, and in FIGS. 4 and 5, 9and 10, 14 and 15, 19 and 20, 24 and 25, 30 and 31, arrows indicate thevectors 66 of magnetization of the material of magnetostrictive parts17, 28, 29, 34, 36 of the core 3.

The vectors 66 of magnetization of the material of magnetostrictiveparts 28 and 29 of the core 3 in FIG. 32 and FIG. 33, as well as thevectors 27 of magnetization of magnetic parts 44, 45, 46, 47, 48, 49,50, 51 and 52, 53, 54, 55, 56, 57, 58, 59 (in FIG. 30, 31, 32, 33) areshown in the form of circles with dots and crosses in the center.

The general principle of operation of the magneto-mechanical converteraccording to the present invention is realized in the following way. Theposition of maxima of intensity of the magnetic field in the workingzone (zone of location of the core 3) of the magnet system 2 are definedpreliminary on the basis of experiments or simulation. In the designed(initial) position the geometrical center 14 of at least one part 17,28, 29, 34, 36 of the core 3, made of a magnetostrictive material, isplaced in one of the maxima of intensity of the magnetic field of magnetsystem 2. Further, in order to realize the displacement of the actuator6, relative rotation of the core 3 and the magnet system 2 isimplemented, thus providing alteration of magnitude and/or direction ofthe vector of intensity of the magnetic field of magnet system 2 in thegeometrical center 14 of at least one part 17, 28, 29, 34, 36 of thecore 3, made of a magnetostrictive material.

The magneto-mechanical converter in the particular embodiments of theinvention (FIG. 1, 6, 11, 16, 21, 26) operates in the following way.When engaging the drive 19 of rotative movement (FIG. 1, 6, 11, 16, 21,26) and the auxiliary drive 62 (FIG. 26), the rotation of the axis 18(FIG. 1, 6, 26), axis 30 (FIG. 11, 16, 21), and axis 60 (FIG. 26)together with the corresponding magnet system 2 mounted on them takesplace. For example, in the designed (initial) position of the magnetsystem 2 the intensity of the magnetic field of this system is orientedalong the axis of the easiest direction of magnetization of the materialof the magnetostrictive parts 17, 28, 29, 34 of the core 3 with apositive magnetostriction, along the axis of the easiest direction ofmagnetization of the magnetostrictive part 36 material with a positivemagnetostriction (FIG. 19, 20), and across the axis of the easiestdirection of magnetization of the magnetostrictive part 36 material witha negative magnetostriction (FIG. 24, 25) of the core 3. With therotation of the magnet system 2 the direction of intensity of themagnetic field in each magnetostrictive part 17, 28, 29, 34, 36 of thecore 3 alters, and in a certain position of the magnet system 2 itchanges by 90° in relation to the vector of intensity of the magneticfield of this system 2 in the designed position of the core 3. Thiscauses the maximum change of the length of the core 3 and, respectively,the maximum displacement of the pusher 7.

The axis 13 of the easiest direction of magnetization of the material ofmagnetostrictive parts 17, 28, 29, 34, 36 of the core 3 in theembodiments of the invention (FIG. 1, 6, 11, 16, 21, 26), as indicatedabove, is coincident with the geometrical axis 12 of symmetry of thementioned parts 17, 28, 29, 34, 36, which (axis 12) passes along thedirection of displacement of the actuator 6, made as a pusher 7.

In the embodiments of the invention shown in FIGS. 1, 6, 11, thedirection of the vector of intensity of the magnetic field in eachmagnetostrictive part 17, 28, 29 of the core 3 changes by 90° at therelative rotation of the magnet system 2 and the core 3 by 90°, as isrepresented in the diagrams of control, shown in FIGS. 4 and 5, 9 and10, 14 and 15 respectively. That is, in FIGS. 4, 9, 14 magnetostrictiveparts 17, 28, 29 are located in the designed (initial) position, thatcorresponds to the maximum of intensity of the longitudinal magneticfield of the magnet system 2 relative to the axis 13 of the easiestdirection of magnetization and to the axis 12 of symmetry of thementioned parts 17, 28, 29 of the core 3, and in FIGS. 5, 10, 15,respectively, in the position, corresponding to the maximum of intensityof transversal magnetic field of magnet system 2 relative to the sameaxes 12, 13 of the magnetostrictive parts 17, 28, 29 of the core 3.

Thus, in these embodiments of the invention (FIGS. 1, 6, 11) at onecomplete revolution of the magnet system 2 (i.e., its revolution by 360°) the core 3 is able to make maximum changes of its linear dimension inthe direction corresponding to the direction of the displacement of thepusher 7 four times.

In the embodiments of the invention shown in FIGS. 16 and 21 thedirection of the vector of intensity of the magnetic field in eachmagnetostrictive part 34, 36 of the core 3 changes by 90° at therelative rotation of the magnet system 2 (FIG. 21) or the main source 4(FIG. 16) of the magnetic field (with the stationary auxiliary source 22of the magnetic field) and the core 3 by 180°. It is represented in thediagrams of control shown in FIGS. 19 and 20, 24 and 25, respectively.That is, in FIGS. 19 and 24 the magnetostrictive parts 34 and 36 arelocated in the designed (initial) position, corresponding to the maximumof intensity of the longitudinal magnetic field (FIG. 19) and to themaxima of intensity of the longitudinal magnetic field (for part 34 witha positive magnetostriction) and transversal magnetic field (for part 36with a negative magnetostriction) of the magnet system 2 (FIG. 24)relative to the axis 13 of the easiest direction of magnetization andthe axis 12 of symmetry of the mentioned parts 34 and 36 of the core 3,and in FIGS. 20 and 25, respectively, in the position, corresponding tothe maximum of intensity of the transversal magnetic field FIG. 20) andto the maxima of intensity of the transversal (for part 34 with apositive magnetostriction) and longitudinal (for part 36 with a negativemagnetostriction) magnetic field of the magnet system 2 (FIG. 25)relative to the same axes 12, 13 of the magnetostrictive parts 34, 36 ofthe core 3.

Thus, in these embodiments of the invention (FIGS. 16 and 21) at onecomplete revolution of the magnet system 2 (i.e., its revolution by360°) the core 3 is able to make maximum changes of its linear dimensionin the direction corresponding to the direction of the displacement ofthe pusher 7 two times.

In the embodiment shown in FIG. 26 the direction of the vector ofintensity of the magnetic field in each of the magnetostrictive part 28, 29 of the core 3 changes by 90° at the rotation, e.g., in oppositedirections with the same angular frequency of the main source 4 and theauxiliary source 22 of the magnetic field of magnet system 2 (FIG. 28,29) by an angle, equal to one-sixteenth (1/16) part of 360°, relative tothe core 3. It is represented in the diagram of control shown in FIGS.30, 31 and FIGS. 32, 33.

That is, in FIGS. 30 and 31 the magnetostrictive parts 28, 29 arelocated in the designed (initial) position, corresponding to the maximumof intensity of the longitudinal magnetic field of magnet system 2relative to the axes 13 of the easiest direction of magnetization andaxes 12 of symmetry of the mentioned parts 28, 29 of the core 3, and inFIGS. 32 and 33--in the position, corresponding to the maximum ofintensity of the transversal magnetic field relative to the same axes12, 13 of the magnetostrictive parts of the core 3.

Thus, in this embodiment (FIG. 26), when the rotation in oppositedirections with the same angular frequency of the main and auxiliarysources 4 and 22 of the magnetic field of the magnet system 2 isperformed, the magnetostrictive parts 28 and 29 of the core 3 are ableto make maximum changes of their linear dimensions in the directioncorresponding to the direction of the displacement of the pusher 7sixteen times at a complete revolution by 360° of each of the sources 4and 22 of the magnetic field.

Practical realization of the present invention has been implemented inaccordance with the embodiment of FIG. 11. The main and auxiliarysources 4, 22 of the magnetic field were made of a Nd--Fe--B typematerial, the main and auxiliary magnetic circuits 21, 33--of steel 3,the core 3 comprised two parts 28, 29 implemented in the form of aparallelepiped of the TbFe₂ material. The overall dimensions of eachmagnet system are as follows: diameter 60 mm, height 51 mm. The overalldimensions of each magnetic circuit 21 and 33 are as follows: diameter60 mm, height 10 mm. The overall dimensions of each of the magneticparts 23, 24, 25, 26 of the sources 4 and 22 of the magnetic field areas follows: 30 mm×20 mm×10 mm. The overall dimensions of each of the twoparts 28, 29 of the core 3 are as follows: length 20 mm, width 4 mm,height 8 mm. The gap between the core 3 and each of the sources 4 and 22of the magnetic field is 1.5 mm, and between the parts 28, 29 of thecore 3 and the axis 30 of rotation of the magnet system 2 is 1 mm. Themagnitude of intensity of the magnetic field in the geometrical centerof the composed core was equal to 360 kA/m. The power of the motor, thatrotates the magnet system 2 while positioning was equal to 5 W. Therelative rotation of the core 3 and the magnet system 2 was implementedaccording to the diagram of FIGS. 14 and 15 (the core is shown as if itrotates in relation to the stationary magnet system). The longitudinalaxis of the core 3 coincided in direction with the axis 13 of theeasiest direction of magnetization of the material of magnetostrictiveparts 28, 29 of the core 3 and with the direction of the vector ofintensity of the magnetic field in the geometrical centers 14 of theparts 28, 29 at the designed position of the magnet system 2 and thecore 3.

The actuator 6 traveled a distance of 30 μm. Thus, in themagneto-mechanical converter of the invention according to theembodiment of FIG. 11, change of the coordinate of the pusher 7 at 30 μmis provided with the power consumption of 5 W (power of the motor, thatrotates the magnet system), while maintaining this coordinate during anyperiod of time requires no power at all.

In the prior art device the similar change of the coordinate of thepusher (30 μm ) required the power of 700 W , and in the process ofmaintaining this coordinate the power consumed by the system was also700 W.

While using the above-described magneto-mechanical converter as avibrator the amplitude of vibrations of the pusher was 15 μm, frequency400 Hz, and the electric power consumed by the motor was 90 W.

Industrial Application

The magneto-mechanical converter can be used in the means of automationas a device for adjustable displacements of objects, primarily for theprecise positioning of actuators of machines and mechanisms, and namelyin precision manipulators, in adaptive optics, for controlling laserbeam movement in processing centers, for displacement of the workingtool in machines, displacement of the knife of microtome, turn of asample in precise crystallographic x-ray devices, displacement of theneedle in tunnel microscopes, displacement of the object table in tunneland electron microscopes, in precise metering devices, in valves forregulating dispense of gaseous and liquid chemical reagents, inpreparing templates of hybrid microcircuits, in valves of hydraulic andpneumatic systems, etc. In addition to this, the magneto-mechanicalconverter can be used in different devices working in the mode ofvibrations, e.g., in metal-working machines for strengthening thesurfaces of machine parts by riveting or burnishing, for facilitatingthe processes of drilling or cutting, in vibropumps, in manualconstruction tools for piercing concrete and rocks, in technologicalequipment, e.g., in vibromachines for making construction concreteblocks, in technology of stimulating the output of the oil and gaswells, etc.

I claim:
 1. A magneto-mechanical converter comprising:a housing; amagnet system mounted in said housing and comprising a main source ofmagnetic field; a core mounted in said housing and having lineardimensions, at least a portion of said core comprising amagnetostrictive material; and an actuator connected to said core andmovable along a displacement direction relative to the housing;wherein:said main source of magnetic field is a permanent magnet; saidmagnet system is mounted in the housing for relative rotation about saidcore, the axis of said relative rotation being oriented such that thelinear dimensions of the core change during relative rotation due toalteration of magnetic flux in the core.
 2. The magneto-mechanicalconverter according to claim 1, wherein said at least a portion of saidcore comprising a magnetostrictive material has a geometric center. 3.The magneto-mechanical converter according to claim 2, wherein the coreis located in a position selected such that the geometric center of saidat least one portion comprising a magnetostrictive material is locatedin a zone of the magnet system which corresponds to a maximum ofintensity of the magnetic field of said magnet system.
 4. Themagneto-mechanical converter according to claim 2, wherein the axis (15)of relative rotation of the magnet system about the core is orientednonparallel in relation to at least one of: (a) a vector of intensity ofthe magnetic field of the magnet system at the geometric center of saidat least one portion of the core that comprises a magnetostrictivematerial when the core is located in the selected position, and (b) ageometric axis of said at least one portion of the core that comprises amagnetostrictive material, said geometric axis being oriented along saiddisplacement direction of the actuator and passing through the geometriccenter of said at least one portion comprising a magnetostrictivematerial.
 5. The magneto-mechanical converter according to claim 3 orclaim 4, wherein the axis of relative rotation of the magnet systemabout the core is located (a) perpendicular to a geometric axis of saidat least one portion of the core that comprises a magnetostrictivematerial said geometric axis passing through the geometric center ofsaid at least one portion along the displacement direction of theactuator, and (b) perpendicular to a vector of intensity of the magneticfield of the magnet system in the geometric center of said at least oneportion of the core that comprises a magnetostrictive material when thecore is in the selected position.
 6. The magneto-mechanical converteraccording to claim 2 or claim 4, wherein the axis of relative rotationof the magnet system about the core passes through the geometric centerof said at least one portion of the core that comprises amagnetostrictive material.
 7. The magneto-mechanical converter accordingto claim 2, or claim 3, or claim 4, comprising a first permanent magnetserving as the main source of the magnetic field, said first permanentmagnet comprising at least two main magnetic parts forming a group andpositioned in one plane such that vectors of magnetization of at leasttwo adjacent ones of said main magnetic parts are oriented in oppositedirections.
 8. The magneto-mechanical converter according to claim 7,wherein the magnet system comprises a second permanent magnet serving asan auxiliary source of the magnetic field, said second permanent magnetcomprising at least two auxiliary magnetic parts forming a group andlocated in one plane such that vectors of magnetization of at least twoadjacent ones of said auxiliary magnetic parts are oriented in oppositedirections, wherein both said main source and said auxiliary source ofthe magnetic field are positioned mirror-symmetrically in relation to aplane perpendicular to the axis of relative rotation of the magnetsystem about the core, and groups of main and auxiliary magnetic parts(23, 24, 37, 38, 39, 25, 26, 40, 41, 42) are oriented in such a way thatthe vectors (27) of magnetization of oppositely positioned main andauxiliary magnetic parts of said main and auxiliary sources of themagnetic field are oriented in opposite directions along the axis ofrelative rotation of the magnet system about the core.
 9. Themagneto-mechanical converter according to claim 8, wherein the groups ofmagnetic parts serving as sources 1of the magnetic field are arranged inthe form of disks, and each of the magnetic parts in the groups has theform of a sector.
 10. The magneto-mechanical converter according toclaim 7 wherein the core comprises three parts which are consecutivelypositioned along a geometric axis of at least one part that comprises amagnetostrictive material, said geometric axis passing through thegeometric center of said at least one part along the displacementdirection of the actuator, wherein outer parts of the core comprise amagnetostrictive material, and a middle part of the core comprises amaterial with elastic modulus and elastic limit that are at least asgreat, by magnitude, as the elastic modulus and elastic limit,respectively, of material of any of said outer parts adjacent to saidmiddle part.
 11. The magneto-mechanical converter according to claim 10,wherein the material of one outer part of the core has a positivemagnetostriction, and the material of another outer part has a negativemagnetostriction.
 12. The magneto-mechanical converter according toclaim 1, wherein the core comprises two identical parallel positionedparts comprising a magnetostrictive material, wherein said parallelpositioned parts of the core are located centrally symmetrically inrelation to the geometrical axis of relative rotation of the magnetsystem about the core.
 13. The magneto-mechanical converter according toclaim 1, or claim 3, or claim 4, wherein the magnet system is suppliedwith a magnetic circuit, and the source of the magnetic field is locatedon the magnetic circuit on the side of the magnetic circuit facing thecore.
 14. The magneto-mechanical converter according to claim 2, orclaim 3, or claim 4, wherein an axis of easiest direction ofmagnetization of the material of said at least one portion comprising amagnetostrictive material passes through the geometric center of said atleast one portion along the displacement direction of the actuator.